1. Field of the Invention
The present invention relates to a method and an apparatus for inspecting a measured object on which an image is formed, and an image forming apparatus.
2. Description of the Related Art
Various printing machines have been proposed which are capable of imparting gloss to a printed item. For example, gloss may be imparted by using a UV varnish, a transparent ink that does not penetrate paper, or by forming dots using a transparent toner. Thus, various gloss distribution inspecting apparatuses have been proposed for inspecting gloss irregularity as well as a density distribution of the printed item.
For example, Japanese Laid-open Patent Publication No. 2005-277678 (Patent Document 1) discusses an apparatus for acquiring density distribution and gloss degree distribution data of a printed item. The apparatus acquires the data by measuring specular reflected light and diffuse reflected light from the printed item as image data by using a camera and two illuminating units.
In order to acquire the gloss degree distribution, data consisting solely of specular reflected light is required. However, when the apparatus discussed in Patent Document 1 is simply applied, it is difficult to image only the specular reflected light with the camera, and the obtained data may include the diffuse reflected light. In addition, in the case of white paper, the specular reflected light may be buried in the strong diffuse reflected light from the white paper.
Further, Patent Document 1 does not discuss any structure for separating the data based on light including both the specular reflected light and the diffuse reflected light into data based solely on the specular reflected light and data based solely on the diffuse reflected light.